Liquid crystal display

ABSTRACT

According to one embodiment, a liquid crystal display comprising a first substrate, a second substrate opposed the first substrate, a liquid crystal layer between the first substrate and the second substrate, a light-shielding layer including a first light-shield formed along a first direction and a second light-shield formed along a second direction and crossing the first light-shield, and a spacer which maintains a gap between the first substrate and the second substrate, the spacer overlapping a crossing region where the first light-shield and the second light-shield cross each other and including an exposed region outside the light-shielding layer in a planar view.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of application Ser. No. 15/454,435,filed Mar. 9, 2017, and is based upon and claims the benefit of priorityfrom Japanese Patent Application No. 2016-048603, filed Mar. 11, 2016,the entire contents of which are incorporated herein by reference.

FIELD

Embodiments described herein relate generally to a liquid crystaldisplay.

BACKGROUND

Liquid crystal displays comprise, for example, a columnar spacer tomaintain the interval between a pair of substrates. The columnar spaceris overlaid on, for example, the pixel electrodes in order to enhancethe adhesion with the substrates. However, the alignment of the liquidcrystal molecules is disordered near the columnar spacer, and thereforea light-shielding layer is disposed to overlap the columnar spacer andits surroundings, thereby decreasing the area of the opening portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a cross section of a display device.

FIG. 2 is a planer view of a display panel.

FIG. 3 is a diagram showing a crossing region and a spacer arranged sothat the centers thereof coincide in a planer view.

FIG. 4 is an diagram showing the widths of a light-shielding layer and aspacer.

FIG. 5 is a diagram showing the crossing region and the spacer arrangedso that the centers thereof separate from each other in a planer view.

FIG. 6 is a cross section of a structure of the display panel.

FIG. 7A is an expanded cross section of a display panel of the casewhere the center of the spacer shifts with respect the center of thecrossing region.

FIG. 7B shows an example of the cross section of the spacer photographedwith an electron microscope.

FIG. 8 is a diagram showing the pixel electrode and the spacer when thedisplay panel shown in FIG. 7A is viewed planarly.

FIG. 9 is a diagram showing an exposed region, a middle region and anoverlapping region.

FIG. 10 is an expanded cross section of the display panel of the casewhere the centers of the spacer and the crossing region coincide in aplaner view.

FIG. 11 is a diagram showing the pixel electrode and the spacer when thedisplay panel shown in FIG. 10 is viewed planarly.

FIG. 12 is a graph showing the relationship between a spacer density anda spacer exposure density.

FIG. 13 is a diagram showing an overlapping region of the case where thecenter of the spacer is separated from the center of the crossing regionin the first direction.

FIG. 14 is a diagram showing an overlapping region of the case where thecenter of the spacer is separated further from the center of a crossingregion in the first direction than that of FIG. 13.

FIG. 15 is a diagram showing an overlapping region of the case where thecenter of the spacer is separated further from the center of thecrossing region in the second direction than that of FIG. 13.

FIG. 16 is a diagram showing an overlapping region of the case where thecenter of the spacer is separated further from the center of thecrossing region in the second direction than that of FIG. 15.

FIG. 17 is a diagram showing an overlapping region of the case where thecenter of the spacer is separated further from the center of thecrossing region in the first direction than that of FIG. 15.

FIG. 18 is a diagram showing an overlapping region of the case where thecenter of the spacer is separated further from the center of thecrossing region in the second direction than that of FIG. 17.

FIG. 19 is a cross section of a display panel when the spacer projectsfrom the second substrate side.

FIG. 20 is a diagram showing the structure of a display panel.

FIG. 21 is a diagram showing the structure of a unit pixel.

FIG. 22 is a diagram showing the structure of the light-shielding layercorresponding to the unit pixel shown in FIG. 21.

FIG. 23 is a diagram showing an example of arrangement of the spacercorresponding to the unit pixel shown in FIG. 21.

DETAILED DESCRIPTION

In general, according to one embodiment, there is provided a liquidcrystal display comprising: a first substrate; a second substrateopposed the first substrate; a liquid crystal layer between the firstsubstrate and the second substrate; a light-shielding layer including afirst light-shield formed along a first direction and a secondlight-shield formed along a second direction and crossing the firstlight-shield; and a spacer which maintains a gap between the firstsubstrate and the second substrate, the spacer overlapping a crossingregion where the first light-shield and the second light-shield crosseach other and including an exposed region outside the light-shieldinglayer in a planar view.

According to another embodiment, there is provided A liquid crystaldisplay comprising: a first substrate; a second substrate opposed thefirst substrate; a liquid crystal layer between the first substrate andthe second substrate; a light-shielding layer including a firstlight-shield formed along a first direction, a second light-shield and athird light-shield formed in a second direction, a first crossing regionwhere the first light-shield and the second light-shield cross eachother, and a second crossing region where the first light-shield and thethird light-shield cross each other, and a spacer including a firstspacer overlapping the first crossing region and a second spaceroverlapping the second crossing region and holding a gap between thefirst substrate and the second substrate, the first spacer including afirst exposed region outside the light-shielding layer, the secondspacer including a second exposed region outside the light-shieldinglayer, the first exposed region located adjacent to the firstlight-shield in a forward direction of the second direction, and thesecond exposed region located adjacent to the first light-shield in abackward direction of the second direction.

Embodiments will be described hereinafter with reference to theaccompanying drawings. The disclosure is merely an example, and properchanges within the spirit of the invention, which are easily conceivableby a skilled person, are included in the scope of the invention as amatter of course. In addition, in some cases, in order to make thedescription clearer, the widths, thicknesses, shapes, etc. of therespective parts are schematically illustrated in the drawings, comparedto the actual modes. However, the schematic illustration is merely anexample, and adds no restrictions to the interpretation of theinvention. Besides, in the specification and drawings, the same elementsas those described in connection with preceding drawings are denoted bylike reference numerals, and a detailed description thereof is omittedunless otherwise necessary.

In the present embodiment, a liquid crystal display device is describedas an example of the display device. For example, the display device isapplicable to various devices such as smartphones, tablet computers,feature phones, computers, TVs, in-car devices, and game consoles. Themajor configuration explained in the present embodiment can also beapplied to, for example, an electronic paper display device comprising acataphoretic element, a display device employing micro-electromechanicalsystems (MEMS), or a display device employing electrochromism.

FIG. 1 is a cross-section of a display device. Note that a firstdirection X is, for example, a direction along a short-side of a displaypanel PNL. A second direction Y is a direction crossing the firstdirection X, which is a direction, for example, along a long-side of thedisplay panel PNL. A third direction Z is a direction crossing the firstdirection X and the second direction Y, which is, for example, a normaldirection to the display panel PNL. In the figure illustrated, the firstdirection X and the second direction Y are orthogonal to each other, andthe third direction Z is orthogonal to both the first direction X andthe second direction Y. The first direction X and the second direction Ymay cross each other at an angle other than orthogonal.

The display device DSP comprises a display area DA and a non-displayarea NDA surrounding the display area DA. The display panel PNLcomprises a first substrate SUB1, a second substrate SUB2 opposing thefirst substrate SUB1, and a liquid crystal layer LC between the firstsubstrate SUB1 and the second substrate SUB2. The second substrate SUB2opposes the first substrate SUB1 along the third direction Z with a gapG therebetween, and spacers SP and sealing materials SE are providedbetween the first substrate SUB1 and the second substrate SUB2. Thespacers SP are arranged at certain intervals in the display area DA, tomaintain the gap G between the first substrate SUB1 and the secondsubstrate SUB2. The spacers SP are formed of, for example, a photoresistsuch as an acrylic resin. The sealing materials SE are provided in thenon-display area NDA so as to attach the first substrate SUB1 and thesecond substrate SUB2 to each other. The sealing materials SE are formedof, for example, a thermosetting resin, photosetting resin or the like.The liquid crystal layer LC is provided to fill the space enclosed bythe first substrate SUB1, the second substrate SUB2 and the sealingmaterials SE.

FIG. 2 is a diagram showing the display panel in a planer view. Theplanar view is a state observed from a forward direction to an oppositedirection along the third direction Z. Or the planar view can be definedas a state of observing the display area DA from a viewpoint establishedin a normal direction to the surface of the display area DA. Note thatnot only in the case of the third direction Z, but in all of the firstto third directions X, Y and Z, the forward direction is a directionpointed by the tip of an arrow, and the opposite direction is adirection opposite to that pointed by the tip of an arrow.

The shape of the display panel PNL in a planer view is rectangular inthe example illustrated, but not particular limited. It may be someother quadrangular shape than that illustrated, such as rhombic ortrapezoid, or other polygonal shape such as triangular or pentagonal.The shape of the display panel PNL in a planer view may contain a curvesuch as of a circle (ellipse) or a sector. Similarly, the shape of thedisplay area DA in a planer view is rectangular in the exampleillustrated, but not particular limited. It may be a polygonal shapeother than rectangular, or may contain a curve such as of a circle or anellipse.

The display panel PNL comprises a light-shielding layer SH. Thelight-shielding layer SH contains, for example, a black resin tosuppress reflection and transmission of light. The light-shielding layerSH includes a peripheral light-shielding layer PRP disposed in thenon-display area NDA, and a plurality of light-shields SH1 and SH2 eachin stripe in the display area DA. The light-shields SH1 are each formedalong the first direction X and arranged with an interval in the seconddirection Y. The light-shields SH2 are each formed in the seconddirection Y to cross the light-shields SH1 while being arranged at aninterval in the first direction X. The light-shields SH1 and SH2 arearranged in a grid shape so as to define apertures AP each by anadjacent pair of light-shields SH1 and a respective adjacent pair oflight-shields SH2. The light entering the display panel PNL is shieldedby the light-shielding layer SH and transmits the apertures AP. Theapertures AP are arranged in a matrix, for example, along the firstdirection X and the second direction Y.

FIG. 3 is a diagram showing a crossing region and a spacer arranged sothat the centers thereof coincide with each other in a planer view.

Spacer SP is overlaid on the light-shielding layer SH. In a planer view,the spacer SP is overlaid on a crossing region CR where thelight-shields SH1 and the light-shields SH2 cross each other, and thespacer includes an exposed region ER exposed to the outside of thelight-shielding layer SH. In the example illustrated, a center CSP ofthe spacer SP is overlaid on the crossing region CR and the spacer SPincludes four exposed regions ER1, ER2, ER3 and ER4. The exposed regionsER1 to ER4 are overlaid on the apertures AP, respectively. The centerCSP may be overlaid on or separated from the center CCR of the crossingregion CR. Here, the center CSP is the geometric center of the figuredefined by edge ED of the spacer SP. The edge ED is equivalent to theoutermost circumference of the spacer SP in a planer view. When thespacer SP is formed into a tapered shape with a bottom and a top thearea of which is smaller than that of the bottom, the edges ED are eachequivalent to an edge of the bottom. Moreover, the center CCR is at anintersection of a central axis AX1 of the light-shield SH1 and a centralaxis AX2 of the light-shield SH2. The central axis AX1 is a virtual linewhich connects a middle point of the light-shield SH1 along the seconddirection Y, and extends in the first direction X. The central axis AX2is a virtual line which connects a middle point of the light-shield SH2along the first direction X, and extends in the second direction Y.

The exposed region ER1 opposes the exposed region ER2 via thelight-shield SH2 along the first direction X, and also opposes theexposed region ER3 via the light-shield SH1 along the second directionY. The exposed region ER4 opposes the exposed region ER3 via thelight-shield SH2 along the first direction X, and opposes the exposedregion ER2 via the light-shield SH1 along the second direction Y, andalso opposes the exposed region ER1 via the crossing region CR.

FIG. 4 is a diagram showing widths of a light-shielding layer and aspacer.

A width W12 of the spacer SP along the first direction X is greater thana width W11 of the second light-shield SH2 along the first direction X.A width W22 of the spacer SP along the second direction Y is greaterthan a width W21 of the first light-shield SH1 along the seconddirection Y. The width W12 and W22 are equivalent to the maximum widthsof the figure defined by the edge ED along the first direction X and thesecond direction Y, respectively. In the example illustrated, the figuredefined by the edge ED is a circle, by which the widths W12 and W22 areequal to each other, and equivalent to the diameter of the circledefined by the edge ED. The widths W11 and W21 are equivalent to themaximum widths of the crossing region CR along the first direction X andthe second direction Y, respectively, for example. The light-shieldinglayer SH does not comprise a light-shield which shields the regionscorresponding to the exposed regions ER1 to ER4. In the exampleillustrated, the width W21 of the light-shield SH1 along the seconddirection Y is uniform at any location. Further, the width W11 of thelight-shield SH2 along the first direction X is also uniform at anylocation in the example illustrated. In other words, the widths W21 andW11 are each constant even at a location close to or separate from thecrossing region CR.

The area of the effective display region of each aperture AP, whichcontributes to display is the area obtained by deducting the area ofeach respective exposed region ER (ER1, ER2, ER3 or ER4) from the areaof each aperture AP. Note here that an total area of the exposed regionER of one spacer SP should desirably be smaller because in thevicinities of the four exposed regions ER1 to ER4, the alignment of theliquid crystal composition of the liquid crystal layer LC may bedisordered to degrade the contrast. Thus, from a viewpoint of improvingthe aperture ratio, which indicates the area ratio of the aperture AP tothe display area DA, it is desirable that the widths W12 and W22 of thespacer SP be small, and also the width W11 and W21 of the light-shieldSH1 and SH2 should desirably smaller in proportion to the decrease ofthe width W11 and W21.

FIG. 5 is a diagram showing a crossing region and a spacer arranged sothat the centers thereof are separate from each other in a planer view.

Here, the departure from a center CSP to a center CCR will be expressedas a displacement DP. In the example illustrated, the direction of thedisplacement DP is opposite to the first direction X, and the dimensionof the displacement DP is less than the radius of the spacer SP. Here,from a viewpoint of suppressing the ratio occupied by the area of theexposed region ER1 to the area of the aperture AP, it is desirable thatthe spacer SP overlap at least the crossing region CR or more desirablythe center CCR. In other words, the degree of the displacement DP shoulddesirably be less than (W12+W11)/2, or more desirably less than or equalto 2/W12.

FIG. 6 is a cross section showing the structure of the display panel.

The display panel PNL comprises a liquid crystal layer LC and an opticalelement OD in addition to the first substrate SUB1 and the secondsubstrate SUB2 shown in FIG. 1. In the structure example illustrated,the display panel PNL is a reflection type with a reflective displayfunction which displays images by selectively reflecting light. Notethat the display panel PNL may be a transmissive display panel with atransmissive display function which displays images by selectivelytransmitting light. Further, the display panel PNL may be atransflective display device with both the transmissive and reflectivedisplay functions.

The first substrate SUB1 comprises a first insulating substrate 10, aninsulating film 11, a plurality of pixel electrodes PE, alignment filmAL1 and the like. Although not illustrated, the first substrate SUB1includes various wiring lines such as control lines CL and signal linesSL, which will be described later with reference to FIG. 20. The firstinsulating substrate 10 is formed from a transparent insulatingsubstrate such as a glass or resin substrate and into a flat plate shapewith a pair of surfaces opposing each other. The insulating film 11 isdisposed on one of the pair of the surfaces of the first insulatingsubstrate 10, which opposes the second substrate SUB2, and is formedfrom, for example, an organic insulating material such as an acrylicresin. The pixel electrodes PE are disposed on the insulating film 11.The alignment film AL1 covers the pixel electrodes PE.

The second substrate SUB2 comprises a second insulating substrate 20, alight-shielding layer SH, a color filter layer CF, an overcoat layer OC,a common electrode CE, an alignment film AL2 and the like. The secondinsulating substrate 20 is formed from a transparent insulatingsubstrate such as a glass or resin substrate and into a flat plate shapewith a pair of surfaces opposing each other. The light-shielding layerSH is located on one of the pair of the surfaces of the secondinsulating substrate 20, which opposes the first substrate SUB1. In theexample illustrated, the light-shielding layer SH opposes a gap betweenan adjacent pair of pixel electrodes PE. The color filter layer CF islocated on the one of the pair of the surfaces of the second insulatingsubstrate 20, which opposes the first substrate SUB1. Although notdescribed in detail, the color filter layer CF includes, for example, ared filter, a green filter and a blue filter. Each color filter overlapsthe light-shielding layer SH by its end. Note that the color filterlayer CF may include a filter of some other color, such as white, or atransparent layer. The overcoat layer OC covers the color filter layerCF. The common electrode CE is located on a side of the overcoat layerOC, which opposes the first substrate SUB1. The common electrode CEopposes the pixel electrodes PE. The common electrode CE is formed froma transparent conductive material such as indium-tin oxide (ITO) orindium-zinc oxide (IZO). The alignment film AL2 covers the commonelectrode CE.

The liquid crystal layer LC is adjacent to the alignment films AL1 andAL2. In the example illustrated, the display panel PNL is of a verticalelectric field type which varies the optical property of the liquidcrystal layer LC by utilizing the electric field produced in the liquidcrystal layer LC along the normal direction to the first substrate SUB1according to the potential difference between the pixel electrode PE andthe common electrode CE. The liquid crystal layer LC contains a liquidcrystal composition which has negative dielectric anisotropy. Note thatthe display panel PNL may be of a lateral electric field type whichproduces an electric field to be utilized, which is parallel to thefirst substrate SUB in the liquid crystal layer LC, or may be an obliqueelectric field type which produces an electric field oblique to thefirst substrate SUB1. In the lateral electric field type panel, both thepixel electrode PE and the common electrode CE are disposed on the firstsubstrate SUB1. Here, the display panel PNL should desirably be of theso-called normally white mode, which exhibits a display state (whitedisplay) when voltage is not applied to the pixel electrode PE, and anon-display state (black display) when voltage is applied. In thedisplay state, the liquid crystal composition is initially aligned alongthe normal direction to the first substrate SUB1 by the alignmentrestriction force of the alignment films AL1 and AL2. In the non-displaystate, the liquid crystal composition is aligned along the directionperpendicular to the electric field since it has negative dielectricanisotropy.

The optical element OD is located on one of the pair of surfaces of thesecond substrate SUB2, which is opposite to the one in contact with theliquid crystal layer LC. The optical element OD comprises, for example,a scattering layer FS, a retardation plate RT, polarizer PL, and thelike. The scattering layer FS is adhered to the second insulatingsubstrate 20, the retardation plate RT is stacked on the scatteringlayer FS, and the polarizer PL is stacked on the retardation plate RT.Note that the structure of the optical element OD is not restricted tothe example illustrated.

The scattering layer FS is an anisotropic scattering layer whichscatters the light entering from a specific direction. In the exampleillustrated, the scattering layer FS has the function to transmit lightentering from the light source LS side without substantially scatteringand scatter the reflection light from a specific direction, that is, thereflection light from the pixel electrode PE. It is desirable to stack aplurality of scattering layers FS for such purposes of extending therange of diffusion, preventing rainbow hues and the like. Theretardation film RT is stacked on the forward-scattering film FS. Theretardation film RT is a quarter-wave plate. For example, theretardation film RT is constituted by stacking a quarter-wave plate anda half-wave plate so as to reduce a wavelength dependency and obtain adesired phase difference within a wavelength range used for colordisplay.

FIG. 7A is an enlarged cross section of a display panel when the centerof a spacer is displaced from to the center of a crossing region. In theexample illustrated, an upper direction is defined as a directionpointed by the arrow of the third direction Z.

The pixel electrode PE1 comprises a reflecting electrode RE1 and atransparent protecting electrode TE1 stacked on the reflecting electrodeRE1. The reflecting electrode RE1 is formed of a metal material havinghigh reflectance to visible light, such as aluminum or silver. Theprotecting electrode TE1 is formed of a transparent conductive materialsuch as ITO or IZO. The reflecting electrode RE1 is disposed on theinsulating film 11 and comprises an upper surface RE1 a located on aside opposing the second substrate SUB2, and a side surface RE1 blocated on a side opposing the other reflecting electrode. From aviewpoint of suppressing the corrosion of the reflecting electrode RE1,which may be caused by current flow, the protecting electrode TE1 shoulddesirably cover the upper surface RE1 a and the side surface RE1 b ofthe reflecting electrode RE1. The protecting electrode TE1 is coveringthe reflecting electrode RE1. The protecting electrode TE1 comprises anupper surface TE1 a located on a side opposing the second substrate SUB2and a side surface TE1 b located on a side opposing the other protectingelectrode.

Spacer SP is disposed on the protecting electrode TE1 and the insulatingfilm 11 so as to be in contact with the upper surface TE1 a and the sidesurface TE1 b. The spacer SP comprises a lower surface SPa located in aside opposing the first substrate SUB1, an upper surface SPb located ona side opposing the second substrate SUB2, and side surface SPc whichconnect the ends of the upper surface SPa and the ends of the lowersurface SPb, respectively to each other. In the example illustrated, theside surface SPc is in contact with the ends of the alignment film AL1.For example, in the manufacturing process for the first substrate SUB1,the alignment film AL1 is formed by a coating/drying step after theformation of the spacers SP. Due to such a manufacturing process, it maybe considered that the alignment film AL1 is formed to have such aconfiguration that it is also formed on the upper surface SPb and theside surface SPc. However, since the material of the alignment film AL1tends to slide down from the upper surface SPb and the side surface SPcof the spacer SP during the period from the coating until the completionof drying, the alignment film AL1 is not substantially formed orextremely thin on the upper surface SPb and the side surface SPc. Forthis reason, the illustration of the alignment film AL1 on the uppersurface SPb and the side surfaces SPc is omitted. The upper surface SPbis in contact with the alignment film AL2 in the example illustrated,but it may be separated from the alignment film AL2. For example, ifmade to function as a auxiliary spacer which assists to hold the gap Gwhen an external force is added to the display panel PNL, the spacer SPis separated from the alignment film AL2 while no external force isbeing applied to the display panel PNL.

In the example illustrated, the area of the lower surface SPa is greaterthan that of the upper surface SPb. When, in a tapered shape, a surfaceof a smaller area is defined as a top surface and the other surfacewhose area is greater is defined as a bottom surface, the spacer SP hasa regular tapered shape in which the lower surface SPa corresponds tothe bottom and the upper surface SPb to the top. Here, the edge EDcorrespond to the respective end of the lower surface SPa. As will belater described with reference to FIG. 19, if the spacer SP has aninversed tapered shape in which the lower surface SPa corresponds to thetop, and the upper surface SPb to the bottom, the edge ED correspond tothe end of the upper surface SPb.

In order to improve the adhesion between the spacer SP and itsunderlayer (the protecting electrode TE1 and the insulating film 11), itis desirable that the area of the adhering surfaces of the spacer SP andthe underlayer attaching together be large. In the example illustrated,the adhering surface of the spacer SP side corresponds to the lowersurface SPa, whereas the adhering surface of the underlayer sidecorresponds to the regions of the upper surface TE1 a and the sidesurfaces TE1 b of the protecting electrode TE1 and the upper surface ofthe insulating film 11, which are in contact with the lower surface SPa.Moreover, for example, the spacer SP has better adhesion with respect toan inorganic material than to an organic material. Here, the protectingelectrode TE1 is made of an inorganic material and the insulating film11 is made of an organic material, and therefore, from a viewpoint ofimproving the adhesion between the spacer SP and the underlayer, it isdesirable that the ratio of the upper surface TE1 a occupies in theadhesion surface of the underlayer be large.

FIG. 7B shows an example of the cross section of a spacer observed underan electron microscope. FIG. 7A is a schematic diagram illustrating aconfiguration example. Note that an actual spacer SP has a cross sectionsuch as shown in FIG. 7A, and may not exhibit such an apparenttrapezoidal shape as shown in FIG. 7B.

In this case, an outline formed where the portion of the spacer SP,which is in tight contact with the underlyaer as shown in FIG. 7B isassumed as the shape of the lower surface SPa. Here, in the portion mostdistant along the third direction Z from the lower surface Spa, astraight line LN parallel to the upper surface of the first insulatingsubstrate 10 is drawn. As to the inclination of the sectional shape ofthe spacer SP with respect to the straight line LN, the region in whichthe amount of change in the third direction Z with respect to the changein the first direction X in a minute space is assumed as the uppersurface SPb, and the region in which the amount of change is 0 or morebut less than 1 is assumed as a side surface SPc.

FIG. 8 is a diagram showing a pixel electrode and a spacer when thedisplay panel shown in FIG. 7A is viewed planarly.

The first substrate SUB1 comprises pixel electrodes PE2 to PE4 inaddition to the pixel electrode PE1. In a planer view, the pixelelectrode PE1 is adjacent to the pixel electrode PE2 along the firstdirection X while interposing the light-shield SH2 therebetween and alsoadjacent to the pixel electrode PE3 along the second direction Y whileinterposing the light-shield SH1 therebetween. The pixel electrode PE4is adjacent to the pixel electrode PE3 along the first direction X whileinterposing the light-shield SH2 therebetween and also adjacent to thepixel electrode PE2 along the second direction Y while interposing thelight-shield SH1 therebetween. As in the case of the pixel electrodePE1, the pixel electrodes PE2 to PE4 comprise reflecting electrodes RE2to RE4 and protecting electrodes TE2 to TE4 stacked on the reflectingelectrodes RE2 to RE4, respectively. In the example illustrated, thespacer SP is disposed to deviate from the crossing region CR to adirection opposite to the first direction X while overlapping the pixelelectrode PE1 and PE3, and has exposed regions ER1 and ER3.

The light-shields SH1 and SH2 overlap an end of each of the reflectingelectrodes RE1 to RE4, and also an end of each of the protectingelectrodes TE1 to TE4. The reflecting electrodes RE1 to RE4 and theprotecting electrodes TE1 to TE4 are extended to apertures AP1 to AP4,respectively. Therefore, the reflecting electrodes RE1 and RE3 and theprotecting electrode TE1 and TE3 are extended to the regions opposingthe exposed regions ER1 and ER2.

The overlapping portions of the spacer SP will now be described whilefocusing the region corresponding to the pixel electrode PE1 withreference to FIG. 9.

FIG. 9 is a diagram including an exposed region, a middle region and anoverlapping region.

The spacer SP illustrated in FIG. 9 is deviated in a similar manner tothat of the spacer SP illustrated in FIG. 8. FIG. 9 includes part (a) inwhich the exposed region ER1 is indicated by diagonally shaded portion,part (b) in which the middle region MR1 is indicated by diagonallyshaded portion, and part (c) in which the overlapping region SR1 isindicated by diagonally shaded portion. The middle region MR1 is aregion overlapping the reflecting electrode RE1 of the spacer SP in aplaner view. The overlapping region SR1 is a region overlapping thepixel electrode PE1 of the spacer SP in a planer view, and itcorresponds to the region overlapping the protecting electrode TE1 ofthe spacer SP.

The exposed region ER1 corresponds to the region defined by the edge EDof the spacer SP and the light-shielding layer SH when the crossingregion CR of the light-shielding layer SH is viewed planarly. Asdescribed in connection with FIG. 4, the spacer SP should desirably besmall from a viewpoint of increasing the ratio of the effective displayregion to the apertures AP in area. However, if the area of the adheringsurface of the spacer SP to its underlayer decreases due to thedownsizing of the spacer SP, the adhesion of the spacer SP to theunderlayer degrades as described in connection with FIG. 7A. Especially,for example, when the entire spacer SP is overlaid on thelight-shielding layer SH in a planer view, the most of the surface ofthe underlayer is occupied by the surface of the insulating film 11,which is formed of an organic material. As a result, the adhesion of thespacer SP to the underlayer further degrades, and thus the spacer SP mayfall off from the substrate. On the other hand, when the spacer SPincludes the exposed region ER1, the adhering surface of the underlayeris the protecting electrode TE1, which is formed of an inorganicmaterial. As a result, the adhesion of the spacer SP to the underlayercan be improved. For this reason, it is desirable for the spacer SP toinclude the exposed region ER1 while reducing the area thereof, from aviewpoint of satisfying both of the expansion the effective display areawhile improving the aperture ratio and the improvement of the adhesionbetween the spacer and the substrate. That is, it is desirable for theexposed region ER1 to be defined by the edge ED and the light-shieldsSH1 and SH2. Note that if the exposed region ER1 is defined by the edgeED and light-shield SH1 without the light-shield SH2, the effectivedisplay area is reduced, and therefore the brightness of the aperturesAP is lowered, which may cause an adverse effect on the visibility ofdisplayed images.

The middle region MR1 is the region difined by the edge ED and the sidesurface RE1 b in a planer view. The middle region MR1 includes theexposed region ER1.

The overlapping region SR1 is the region defined by the edge ED and theside surface TE1 b in a planer view. The overlapping region SR1 includesthe middle region MR1. Therefore, the overlapping region SR1 includesthe exposed region ER1. In other words, the middle region MR1 is smallerthan the overlapping region SR1 in area and greater than the exposedregion ER1. From a viewpoint of securing a sufficient adhesion betweenthe spacer and the substrate, the ratio of the total area of theoverlapping region occupied in the area of one spacer in a planer viewshould desirably be 25%.

Note that in this embodiment, the center CSP and the center CCR mayoverlap in a planer view as described with reference to FIG. 3. Suchconfiguration examples will be described with reference to FIGS. 10 and11.

FIG. 10 is an enlarged cross section of the display panel when thecenter of the spacer coincides with the center of the respectivecrossing region in a planer view.

This configuration example is different from that illustrated in FIG. 7in that the spacer SP overlaps the pixel electrode PE2. The protectingelectrode TE2 includes an upper surface TE2 a and a side surface TE2 bas in the case of the pixel electrode PE1. The spacer SP overlaps thereflecting electrode RE2 and the protecting electrode TE2, and is incontact with the upper surface TE2 a and the side surface TE2 b.

FIG. 11 is a diagram showing the pixel electrode and the spacer when thedisplay panel shown in FIG. 10 is viewed planarly.

The spacer SP includes overlapping regions SR1 to SR4. The overlappingregions SR2 to SR4 are regions which overlap the pixel electrodes PE2 toPE4 of the spacer SP and include the exposed regions ER2 to E4,respectively, and correspond to the regions of the spacer SP, whichoverlap the protecting electrodes TE2 to TE4, respectively. For example,the overlapping regions SR1 to SR4 each have a shape point-symmetricalwith respect to the center CSP and the overlapping regions SR1 to SR4are equal to each other in area.

FIG. 12 shows a graph showing the relationship between the spacerdensity and the spacer exposure density. FIG. 12 illustrates therelationship of the spacer exposure density to the spacer density basedon a displacement DP of the spacer SP described with reference to FIG.5. The horizontal axis of the figure indicates the spacer density, whichis the ratio of the total area of all the spacers SP occupied in thedisplay area DA in a planer view. The vertical axis indicates the spacerexposure density, which is the ratio of the total area of all theexposed regions occupied in the display area DA in a planer view. As thespacer exposure density is higher, the area of the region whichcontributes to display decreases, and therefore the spacer exposuredensity should desirably be low.

The dotted line in the graph indicates the change in the spacer exposuredensity with respect to the spacer density when the displacement DP isconstant in the state of: DP>(W11+W12)/2, that is, while the spacer SPis apart from the crossing region CR in a planer view. The solid lineindicates the change in the spacer exposure density with respect to thespacer density when the displacement DP is constant in the state of:DP<(W12)/2, that is, the spacer SP opposes the centers CCR. An exposuredensity difference DD represents the difference in the spacer exposuredensity for the same spacer density. As the exposure density differenceDD is larger, the spacer density becomes larger.

From the graph, it can be understood that in the case where the spacerSP is disposed so as to be partially exposed from the light-shieldinglayer SH, the crossing regions CR and the spacer SP has the followingrelationship in position. That is, when the spacer is disposed to bedeviated slightly from the respective crossing regions CR, the spacerexposure density to the spacer density is decreased as the entiredisplay panel PNL, which, as a result, contributes to improvement in theaperture ratio, as compared to the case where the spacer SP is deviatedgreatly from the crossing region CR so as to be substantially disposedat positions irrelevant to the crossing region CR.

According to this embodiment, the display device DSP comprises thelight-shielding layer including the light-shields SH1 and thelight-shields SH2, and the spacers SP overlapping the crossing regionsCR of the light-shields SH1 and light-shields SH2 and including theexposed regions ER1. With this structure, the total area of theoverlapping regions where the spacers overlap the pixel electrodes canbe increased, thereby improving the adhesion between the substrate andthe spacers, and at the same time, the increase in the total area of theexposed regions can be suppressed, thereby suppressing the reduction ofthe area which contributes to display. As described in connection withFIG. 12, according to this embodiment, as the spacer density requiredincreases, the spacer exposure density can be reduced more, as comparedto the case where the spacers are apart from the crossing regions whenby viewed planarly. Therefore, it is possible to provide a liquidcrystal display which can suppress the degradation of the displayquality.

Here, the widths W11 and W21 of each spacer SP are greater than thewidth W12 of the light-shield SH2 and the width W22 of light-shield SH1respectively. With this structure, a sufficient overlapping region areacan be reserved in the display device, thereby making it possible toachieve excellent adhesion between the spacers and the substrate.

Especially, in the configuration example in which the spacers SP overlapthe centers CCR of the respective crossing regions CR, the exposedregions ER1 can be suppressed, and therefore the total area of theexposed regions in the liquid crystal display can be decreased.

Moreover, in the configuration example in which the exposed regions ER1are each defined by the edge ED of the respective spacer SP and thelight-shields SH1 and SH2, the total area of the exposed regions can besuppressed as compared to the configuration example in which the exposedregions ER1 are each defined only by the edge ED and the light-shieldSH1 or the light-shield SH2.

In the configuration example in which the pixel electrodes each comprisethe protecting electrode stacked on the reflecting electrode and theprotecting electrode covers the upper surface and the side surface ofthe reflecting electrode, the corrosion of the reflecting electrode canbe suppressed.

Since the display device DSP is a liquid crystal display of the normallywhite mode, the lowering of the contrast, which may result from thedisorder of the initial alignment of the liquid crystal composition nearthe exposed regions can be suppressed more as compared to that of thenormally black mode.

Next, a modified configuration example will be described with referenceto FIGS. 13 to 19. As shown in FIG. 3 or 5, in the disposition of aspacer SP in a crossing region CR of the light-shielding layer SH, it isdesirable to have two or more exposed regions ER each defined by theedge ED of the spacer SP and the light-shields SH1 and SH2, which areseparated from each other in the configuration. Such a configuration ismore preferable that there should be three or more exposed regions ER sopartitioned, or most preferably, four exposed regions ER so partitioned.Moreover, it is desirable that at least two of these exposed regions ERbe tightly in contact with the protecting electrode TE. Further, as willbe described below, it is preferable that one spacer SP include two ormore overlapping regions SR opposing each other along the firstdirection X or the second direction Y, or more preferably, three or moreoverlapping regions SR, or still more preferably, four overlappingregions SR. In each overlapping region SR, the spacer SP and theprotecting electrode TE, formed from an inorganic material, shoulddesirably be tightly attached to each other. With the structure that aplurality of exposed regions ER (overlapping regions SR) are arranged tobe separated from each other, these regions, which have strong adhesionto the spacer SP, can be dispersed along the edge ED.

In such modified examples as described above, advantageous effectssimilar to those described above can be obtained.

FIG. 13 is a diagram showing overlapping regions when the center of aspacer is separated from the center of a respective crossing region inthe first direction.

This modified example is different from the configuration exampleillustrated in FIG. 8 in that the spacer SP comprises overlappingregions SR2 and SR4.

The direction of the displacement DP is opposite to the first directionX and the overlapping region SR1 is larger than the overlapping regionSR2. Here, for example, the overlapping regions SR1 and SR2 areaxisymmetrical to the overlapping regions SR3 and SR4, respectively,over the light-shield SH1, and the areas of the overlapping regions SR1and SR2 are equal to those of the overlapping regions SR3 and SR4,respectively.

FIG. 14 is a diagram showing overlapping regions when the center of aspacer is separated from the center of a crossing region in the firstdirection further than that shown in FIG. 13.

In this modified example, the direction of the displacement DP is thesame as that of FIG. 13, and the dimension of the displacement DP islarger.

The spacer SP includes the overlapping regions SR1 and SR3 and isseparated from the pixel electrodes PE2 and PE4 in a planer view.Moreover, the spacer SP overlaps the respective crossing region CR andis separated from the center CCR in a planer view. In such a case, it isdesirable that the overlapping region SR1 be defined by the edge ED, aportion extending from the side surface TE1 b along the first directionX, and another portion extending along the second direction Y, from aviewpoint of balancing between the area of the regions which contributeto display and the adhesion of the spacer, which have a trade-offrelationship.

FIG. 15 is a diagram showing overlapping regions when the center of aspacer is separated from the center of a crossing region in the seconddirection further than that of FIG. 13. This modified example isdifferent from that shown in FIG. 13 in that the direction of thedisplacement DP is opposite to the first direction X and also oppositeto the second direction Y.

Each spacer SP includes overlapping regions SR1 to SR4. The overlappingregion SR1 is larger than the overlapping region SR2 or SR3 in area. Theoverlapping region SR4 is smaller than the overlapping region SR2 or SR3in area. In the example illustrated, the overlapping region SR2 issmaller than the overlapping region SR3 in area. The overlapping regionsSR2 to SR4 need not each include an exposed region and in the exampleillustrated, the overlapping regions SR2 and SR4 are entirely overlaidon the light-shielding layer SH.

FIG. 16 is a diagram showing overlapping regions when the center of aspacer is separated from the center of a respective crossing region inthe second direction further than that of FIG. 15.

In this modified example, the dimension of the displacement DP along thesecond direction Y is greater than that of the modified exampleillustrated in FIG. 15.

Each spacer SP includes overlapping regions SR1 to SR3 and is separatedfrom a pixel electrode PE4 in a planer view. The overlapping region SR1is greater than the overlapping region SR2 or SR3 in area. In theexample illustrated, the area of the overlapping region CR2 is equal tothat of the overlapping region SR3. The overlapping regions SR2 and SR3may not each include an exposed region and in the example illustrated,the overlapping regions SR2 and SR3 are entirely overlaid on thelight-shielding layer SH.

FIG. 17 is a diagram showing overlapping regions when the center of aspacer is separated from the center of a respective crossing region inthe first direction further than that shown in FIG. 15.

In this modified example, the dimension of the displacement DP along thefirst direction X is greater than that of the modified exampleillustrated in FIG. 15.

Each spacer SP includes overlapping regions SR1 and SR3 and is separatedfrom pixel electrodes PE2 and PE4 in a planer view. The overlappingregion SR1 is greater than the overlapping region SR3 in area. In theexample illustrated, the overlapping region SR3 includes an exposedregion, but it may be entirely overlaid on the light-shielding layer SH.

FIG. 18 is a diagram showing an overlapping region when the center of aspacer is separated from the center of a respective crossing region inthe second direction further than that shown in FIG. 17.

In this modified example, the dimension of the displacement DP along thesecond direction Y is greater than that of the modified exampleillustrated in FIG. 17.

Each spacer SP includes an overlapping region SR1 and is separated frompixel electrodes PE2 to PE4 in a planer view. From a viewpoint ofbalance between the area of the regions which contribute to display andthe adhesion of the spacer, it is desirable that each spacer SP overlapa corner TE1 c formed by the portion of the side surface TE1 b,extending in the first direction X and the portion extending in thesecond direction Y in a planer view.

FIG. 19 shows a cross section of a display panel when a spacer projectsout from the second substrate side.

This modified example is different from that illustrated in FIG. 10 inthat a spacer SP projects from a second substrate SUB2 to a firstsubstrate SUB1.

The spacer SP has the so-called inverse tapered shape with an uppersurface SPb being greater in area than a lower surface SPa. The uppersurface SPb is in contact with a common electrode CE. Here, the edge EDis equivalent to an end of the upper surface SPb. The lower surface SPaopposes an alignment film AL1 and is in contact therewith in the exampleillustrated.

Next, the configuration of a reflective display panel PNL of an areagradation mode will be described. For example, such a display panel PNLis a reflective type with the reflective display function which displaysimages by selectively reflecting light entering from the display surfaceside, such as outdoor daylight and auxiliary light, by each segment SG.In such a configuration example as well, an advantageous effect similarto that described above can be obtained.

FIG. 20 is a diagram showing the configuration of a display panel. Inthe example illustrated, a display device DSP comprises a driving moduleDR, etc. in a display panel PNL.

The display panel PNL comprises, in a display area DA, signal lines SL,control lines CL, unit pixels PX, wiring lines and source lines (notshown) which transmit various types of voltages, etc. The signal linesSL are arranged along in the first direction X. The control lines CL arearranged along the second direction Y crossing the first direction X.The unit pixels PX are arranged in a matrix in the X-Y plane defined bythe first direction X and the second direction Y.

Each unit pixel PX is a minimum unit which constitutes a color image.Such a unit pixel PX comprises a plurality of segments (, which may besimply called pixels hereinafter) SG. One unit pixel PX comprises aplurality of sub-pixels, which will be described later. For example, oneunit pixel PX comprises a sub-pixel displaying red, a sub-pixeldisplaying green and a sub-pixel displaying blue. The unit pixel PX maycomprise, in addition to the sub-pixels of three colors described above,a sub-pixel displaying a color other than those, such as white. Eachsub-pixel comprises a plurality of segments SG.

The driving module DR comprises a signal line driving module D1 and acontrol line driving module D2. The driving module DR may be formed in anon-display area NDA of the display panel PNL, built in an IC chipmounted in the display panel PNL, or formed in a flexible printedcircuit board connected to the display panel PNL.

The signal lines SL are each connected to the signal line driving moduleD1. The signal line driving module D1 outputs, for example, a signalpotential corresponding to a predetermined gradation to thecorresponding signal line SL. The control lines CL are each connected tothe control line driving module D2. The control line driving module D2outputs a control signal for controlling the write operation of thesignal potential to a segment SG to the corresponding control line CL.In addition, the driving module DR may further comprise a driving timinggeneration circuit, a power supply circuit, etc.

FIG. 21 is a diagram showing a configuration of the unit pixel.

The unit pixel PX includes four sub-pixels P1 to P4. The sub-pixels P1and P2 are arranged to be adjacent to each other along the firstdirection X. The sub-pixels P3 and P4 are arranged to be adjacent toeach other along the first direction X. The sub-pixels P1 and P3 arearranged to be adjacent to each other along the second direction Y. Thesub-pixels P2 and P4 are arranged to be adjacent to each other along thesecond direction Y. Here, in the unit pixel PX, a straight lineextending in the first direction X is defined as a boundary line B1 anda straight line extending in the second direction Y as a boundary lineB2. The boundary line B1 is equivalent to the central axis of alight-shield SHX2, which will be described later and the boundary lineB2 is equivalent to the central axis of the light-shield SHY2, whichwill be also described later. The sub-pixel P1 is adjacent to thesub-pixel P2 via the light-shield SHY2 interposed therebetween, andadjacent to the sub-pixel P3 via the light-shield SHX2 interposedtherebetween. The sub-pixel P4 is adjacent to the sub-pixel P3 via thelight-shield SHY2 interposed therebetween, and adjacent to the sub-pixelP2 via the light-shield SHX2 interposed therebetween.

The sub-pixels P1 to P4 display different colors, respectively. Forexample, the sub-pixel P1 displays green (G), the sub-pixel P2 displaysred (R), the sub-pixel P3 displays blue (B), and the sub-pixel P4displays white (W). Such color display is realized by disposing thecorresponding color filters to oppose the respective sub-pixels P1 toP4.

The sub-pixels P1 and P2 arranged along the first direction X have thesame area. Each of the sub-pixels P1 and P2 is constituted into aquadrangular shape having a length LX/2 along the first direction X anda length LYa in the second direction Y. In the example illustrated, eachof the sub-pixels P1 and P2 is constituted into a laterally elongatedrectangular shape in which the length LX/2 is greater than the lengthLYa.

The sub-pixels P3 and P4 arranged along the first direction X have thesame area. The area of the sub-pixels P3 and P4 differs from that of thesub-pixels P1 and P2. Each of the sub-pixels P3 and P4 is constitutedinto a quadrangular shape having a length LX/2 along the first directionX and a length LYb along the second direction Y. The length LYb isgreater than the length LYa. In the example illustrated, each of thesub-pixels P3 and P4 is constituted into a longitudinally elongatedrectangular shape in which the length LX/2 is less than the length LYa.

That is, in this configuration example, the sub-pixel P1 and thesub-pixel P3 are arranged along the second direction Y, and thesub-pixel P1 exhibits a laterally elongated rectangular shape, whereasthe sub-pixel P3 exhibits a longitudinally elongated rectangular shapewhile sharing the length along the first direction X. Here, if an aspectratio A of each sub-pixel is defined by the length along the seconddirection Y/the length along the first direction X, the aspect ratio A1of the sub-pixel P1 can be expressed as 0<A1<1, and the aspect ratio A3of the sub-pixel P3 as 1<A3. The relationship between the sub-pixel P2and the sub-pixel P4 is likewise.

Moreover, the sub-pixel P1 and the sub-pixel P3 have the same lengthLX/2 along the first direction X. The length LYa of the sub-pixel P1along the second direction Y is less than the length LYb of thesub-pixel P3 along the second direction Y. Therefore, the area of thesub-pixel P3 is greater than that of the sub-pixel P1. Similarly, thearea of the sub-pixel P4 is greater than that of the sub-pixel P2.

In each unit pixel PX, the sub-pixel P1 and the sub-pixel P2 areaxisymmetrical to each other with respect to the boundary line B2.Similarly, the sub-pixel P3 and the sub-pixel P4 are axisymmetrical toeach other with respect to the boundary line B2. The segments SG11 toSG13 which constitute the sub-pixel P1 are smaller in area than thesegments SG31 to SG33 which constitute the sub-pixel P3, respectively.Thus, the configuration of the sub-pixel P3 and that the sub-pixel P1are asymmetrical to each other with respect to the boundary line B1.Similarly, the segments SG21 to SG23 which constitute the sub-pixel P2are smaller in area than the segments SG41 to SG43 which constitute thesub-pixel P4, respectively. Thus, the configuration of the sub-pixel P4and that of the sub-pixel P2 are asymmetrical to each other with respectto the boundary line B1.

The geometrical center PXC of each unit pixel PX is defined as anintersection of two diagonal lines (dotted line in the figure) of thequadrangle (square in the example illustrated) defined by the outercircumference of the unit pixel PX. Each unit pixel PX has anaxisymmetrical configuration with respect to the boundary line B2, thegeometrical center PXC is located on the boundary line B2. Further, eachunit pixel PX has an asymmetrical configuration with respect to theboundary line B1, the geometrical center PXC is separated from theboundary line B1. That is, the location of the geometrical center PXCdiffers from that of the intersection PXN between the boundary lines B1and B2.

The configuration of each sub-pixel will be described in detail. In thefollowing description, the sub-pixel P1 will be described as an exampleand the detailed description of the other sub-pixels will be omitted.

The sub-pixel P1 comprises three segments SG11 to SG13 for displaying3-bit gradation.

The segment SG11 is equivalent to the region of the quadrangle locatedin a central portion in the sub-pixel P1 (that is, a middle point in thelength LYa/2 of the sub-pixel P1 along the second direction Y or aregion including the location where the distance from the boundary lineB1 along the second direction Y is LYa/2). The segment SG11 includes apair of sides 11A and 11B along the first direction X and a pair ofsides 11C and 11D along the second direction Y.

The segment SG12 is located on a side closer to the geometrical centerPXC as compared to the segment SG11. The segment SG12 is equivalent toan L-shaped region formed along the sides 11A and 11C. The segment SG12is adjacent to the sub-pixel P3 via the boundary line B1 interposedtherebetween and also adjacent to the sub-pixel P2 via the boundary lineB2 interposed therebetween.

The quadrangle region constituted by the segments SG11 and SG12 issimilar to the quadrangle region of the segment SG11.

The segment SG13 is located on a side further from the geometricalcenter PXC as compared to the segment SG11. The segment SG13 isequivalent to an L-shaped region formed along the sides 11B and 11D.Further, the segment SG13 extends in the first direction X over the side11B and is adjacent to a portion of the segment SG12. Furthermore, thesegment SG13 extends in the second direction Y over the side 11D and isadjacent to a portion of the segment SG12. The segment SG13 is greaterin area than the segment SG12. The segment SG13 surrounds the segmentSG11 together with the segment SG12.

The quadrangle region constituted by the segments SG11, SG12 and SG13 issimilar to the quadrangle region of the segment SG11.

In a central part of the sub-pixel P1, the three segments SG11 to SG13are arranged along the first direction X while the segment SG11 being atthe center. In the example illustrated, the segment SG13, the segmentSG11 and the segment SG12 are arranged in this order along the firstdirection X at positions where the distance from the boundary line B1along the second direction Y is LYa/2.

The area ratio between the segment SG11, the segment SG12 and thesegment SG13 is, for example, 1:2:4 (=2⁰:2¹:2²). The area ratio used inthis embodiment is based only on the area of the region whichsubstantially contributes to display in each segment, and the area ofthe region overlapping the spacer SP or the light-shielding layer SH,which does not contribute to display, is not included. But such astructure is also employable that the area ratio between the segmentsincluding the spacer SP is set to 1:2:4. Note that the area ratio of thesegments SG11 to SG13 is not limited to the above-described example.

The segment SG11 is a display region equivalent to the least significantbit (for example, 2⁰) in a 3-bit area gradation. The segment SG13 is adisplay region equivalent to the most significant bit (for example, 2²)in the 3-bit area gradation. The segment SG12 is a display regionequivalent to the middle bit (for example, 2¹) in the 3-bit areagradation. By combinations of the segments SG11 to SG13, it is possibleto achieve the 3-bit area gradation display.

The relationship in position among twelve segments which constitute theunit pixel PX illustrated is as follows. That is, focusing on thesub-pixels P1 and P2 arranged along the first direction X, the threesegments SG11 to SG13 of the sub-pixel P1 and the three segments SG21 toSG23 of the sub-pixel P2 are axisymmetrical respectively to each otherwith respect to the boundary line B2. Further, focusing on thesub-pixels P3 and P4 arranged along the first direction X, the threesegments SG31 to SG33 of the sub-pixel P3 and the three segments SG41 toSG43 of the sub-pixel P4 are axisymmetrical respectively to each otherwith respect to the boundary line B2.

In a central part of the sub-pixel P2, the three segments SG21 to SG23are arranged along the first direction X. In a central part of thesub-pixel P3, the three segments SG31 to SG33 are arranged along thefirst direction X. In a central part of the sub-pixel P4, the threesegments SG41 to SG43 are arranged along the first direction X. Notethat in the example illustrated, the segment SG33, the segment SG31, thesegment SG32, the segment SG42, the segment SG41 and segment SG43 arearranged in this order along the first direction X at positions wherethe distance from the boundary line B1 along the second direction Y isLYb/2. Further, the three segments SG11 to SG13 are arranged in thesub-pixel P1 along the first direction X and the three segments SG31 toSG33 arranged in the sub-pixel P3 along the first direction X arelocated at a pitch along the second direction Y, which is approximately½ of the length LY of the unit pixel PX along the second direction Y.

The segments SG11 to SG13 each comprise a pixel electrode of acorresponding shape and the pixel electrodes of the segments areseparated from each other.

FIG. 22 is a diagram showing the structure of the light-shielding layercorresponding to the unit pixel shown in FIG. 21. In the figure, it isassumed that the light source is located on a negative side along thesecond direction Y, and the main observation angle orientation is on apositive side along the second direction Y. Here, the main observationangle direction is equivalent to an orientation in which the directionof observation of the reflective display panel PNL shown in FIG. 6 bythe user is orthogonally projected on the X-Y plane. The mainobservation angle orientation is set for the maximum brightness (or thehighest reflectivity) by reflecting the light entering the display panelPNL from the light source LS and scattering the reflecting light by thescattering layer FS. When the main observation angle orientation is on aright side of the second direction Y, color mixture easily occurs in thesub-pixels arranged along the second direction Y as compared to thesub-pixels arranged along the first direction X. For example, in thesub-pixels P1 and P3, most of the light reflected by the sub-pixel P1penetrates the green color filter disposed on the sub-pixel P1, but partof the reflection light in the sub-pixel P1 penetrates the blue colorfilter disposed on the sub-pixel P3, thereby easily causing colormixture.

The light-shielding layer SH comprises light-shields SHX1 to SHX3extending along the first direction X and light-shields SHY1 to SHY3extending along the second direction Y, thus partitioning into thesub-pixels P1 to P4. The light-shields SHX1 to SHX3 have the same widthW1. The light-shields SHY1 to SHY3 have the same width W2. The width W1differs from the width W2. For example, the width W1 of the light-shieldSHX2 located between the sub-pixels P1 and P2 and the sub-pixels P3 andP4 is greater than the width W2 of the light-shield SHY2 located betweenthe sub-pixels P1 and P3 and the sub-pixels P2 and P4.

As shown in the figure, the light-shielding layer SH is arranged tolocate between adjacent segments. For example, the light-shield SHX4extends along the first direction X and is located between the segmentsSG11 and SG13, between the segments SG12 and SG13, between the segmentsSG22 and SG23 and between the segments SG21 and SG23. The light-shieldSHX5 extends along the first direction X and is located between thesegments SG31 and SG33, between the segments SG32 and SG33, between thesegments SG42 and SG43 and between the segments SG41 and SG43. Thelight-shield SHY4 extends along the second direction Y and is locatedbetween the segments SG11 and SG13, between the segments SG12 and SG13,between the segments SG31 and SG33 and between the segments SG32 andSG33. The light-shield SHY5 extends in the second direction Y and islocated between the segments SG21 and SG23, between the segments SG22and SG23, between the segments SG41 and SG43 and between the segmentsSG42 and SG43. The light-shields located between respective segmentshave substantially the same width, for example, has the width W2 same asthat of the light-shield SHY2.

For example, the light-shielding layer SH includes a crossing region CR1where the light-shields SHX1 and SHY1 cross each other, a crossingregion CR2 where the light-shields SHX1 and SHY2 cross each other, acrossing region CR3 where the light-shields SHX1 and SHY3 cross eachother, a crossing region CR4 where the light-shields SHX2 and SHY1 crosseach other, a crossing region CR5 where the light-shields SHX2 and SHY4cross each other, a crossing region CR6 where the light-shields SHX2 andSHY2 cross each other, a crossing region CR7 where the light-shieldsSHX2 and SHY5 cross each other, a crossing region CR8 where thelight-shields SHX2 and SHY3 cross each other, a crossing region CR9where the light-shields SHX5 and SHY2 cross each other, a crossingregion CR10 where the light-shields SHX3 and SHY1 cross each other, acrossing region CR11 where the light-shields SHX3 and SHY2 cross eachother and a crossing region CR12 where the light-shields SHX3 and SHY3cross each other.

According to the configuration example as described above, even if partof the reflection light in one sub-pixel is reflected toward anothersub-pixel in those arranged along the second direction Y, such partiallight is shielded by the light-shield SHX2, thereby making it possibleto suppress the color mixture. Thus, degradation in display quality canbe suppressed.

FIG. 23 is a diagram showing an example of arrangement of the spacerscorresponding to the unit pixel shown in FIG. 21.

The unit pixel PX includes spacers SP1 to SP12, for example, near thecrossing regions CR1 to CR12, respectively. The spacers SP1 to SP12 areoverlaid on the light-shielding layer SH, and overlap the crossingregions CR1 to CR12, respectively. The centers of the spacers SP1 toSP12 are separated various directions with respect to the centers of thecrossing regions CR1 to CR12, respectively, in a planer view. The arrowsof the spacers in FIG. 23 each show the deviating direction of eachrespective spacer with respect to the center of each respective crossingregion. For example, the spacer SP6 overlaps the crossing region CR6 ina planer view and is deviated in the first deviating direction withrespect to the center of the crossing region CR6, whereas the spacer SP9is deviated in the second deviating direction different from the firstdeviating direction with respect to the center of the crossing regionCR9 in a planer view. Among the spacers SP2, SP6, SP9, and SP11 disposedalongside the light-shield SHY2 and arranged along the second directionY, the deviating directions of the spacers SP2, SP9 and SP11 each have aforward-direction component of the first direction X, whereas thedeviating direction of the spacer SP9 has a backward direction componentof the first direction X. Among the spacers SP4, SP5, SP6, SP7 and SP8disposed alongside the light-shield SHX2 and arranged along the firstdirection X, the deviating directions of the spacers SP5 and SP8 eachhave a forward direction component of the second direction Y, whereasthe deviating directions of the spacer SP4, SP6, and SP7 each have abackward direction component of the second direction Y.

The spacers SP1 to SP12 include the exposed regions E1 to E12,respectively, exposed to the outside of the light-shielding layer SH ina planer view. The exposed regions E1 to E12 are exposed in variousdirections with respect to the crossing regions CR1 to CR12,respectively, in a planer view. Focusing on, for example, the spacersSP2, SP6, SP9, and SP11 disposed alongside the light-shield SHY2 andarranged along the second direction Y, the exposed regions E2, E9 andE11 included in the spacer SP2, SP9, and SP11 are located adjacent tothe light-shield SHY2 in the forward direction of the first direction X,whereas the exposed region E6 of the spacer SP6 is located adjacent tothe light-shield SHY2 in the backward direction of the first directionX. That is, the exposed region E6 is located on opposite side to theexposed regions E2, E9 and E11 while interposing the light-shield SHY2therebetween. Further, focusing on, for example, the spacers SP4, SP5,SP6, SP7 and SP8 disposed alongside the light-shield SHX2 and arrangedalong the first direction X, the exposed regions E5 and E8 included inthe spacer SP5 and SP8 are located adjacent to the light-shield SHX2 inthe forward direction of the second direction Y, whereas the exposedregions E4, E6 and E7 of the spacers SP4, SP6, and SP7 are locatedadjacent to the light-shield SHX2 in the backward direction of thesecond direction Y. That is, the exposed region E5 and E8 are located onopposite side to the exposed regions E4, E6 and E7 while interposing thelight-shield SHX2 therebetween.

According to the configuration example described above, the spacers SP1to SP12 include the exposed regions E1 to E12, respectively. A pluralityof spacers disposed alongside the light-shield extending along thesecond direction Y, the exposed region of at least one spacer is locatedadjacent to a light-shield in the forward direction of the firstdirection X and the exposed region of at least one spacer is locatedadjacent to a light-shield in the backward direction of the firstdirection X. With this stricture, even if the first substrate SUB1deviates to the forward direction or backward direction of the firstdirection X with respect to the second substrate SUB2, it is possible tosuppress the increase in area of the exposed regions and therefore tosuppress deterioration of display quality.

Moreover, a plurality of the spacers disposed alongside the light-shieldextending in the first direction X, the exposed region of at least onespacer is located adjacent to a light-shield in the forward direction ofthe second direction Y and the exposed region of at least one spacer islocated adjacent to a light-shield in the backward direction of thesecond direction Y. With this structure, even if the first substrateSUB1 deviates to the forward direction or backward direction of thesecond direction Y with respect to the second substrate SUB2, it ispossible to suppress the increase in area of the exposed regions andtherefore suppress deterioration of display quality. Thus, even if thefirst substrate SUB1 and the second substrate SUB2 deviate with respectto each other in any direction on the X-Y plane defined by the firstdirection X and the second direction Y, it is possible to suppress thearea of the exposed regions of the spacers and suppress deterioration ofdisplay quality.

As described above, according to this embodiment, the display devicewhich can suppress deterioration of display quality can be provided.

While certain embodiments have been described, these embodiments havebeen presented by way of example only, and are not intended to limit thescope of the inventions. For example, the embodiments employ thestructure in which with the widths of the light-shield SH1 and SH2 aregreater than the interval between of an adjacent pair of reflectingelectrodes RE or that of protecting electrodes TE; however it is alsopossible to employ such a structure that either one or both of thewidths of the light-shield SH1 and SH2 are less than the intervalbetween these reflecting electrodes RE or that of the protectingelectrode TE.

Indeed, the novel embodiments described herein may be embodied in avariety of other forms; furthermore, various omissions, substitutionsand changes in the form of the embodiment described herein may be madewithout departing from the spirit of the invention. The accompanyingclaims and their equivalents are intended to cover such forms ormodifications as would fall within the scope and spirit of theinventions.

What is claimed is:
 1. A liquid crystal display comprising: a firstsubstrate including a control line, a signal line and a first pixelelectrode; a second substrate opposed to the first substrate andincluding a color filter overlapping the first pixel electrode and alight-shielding layer including a first light-shield formed along afirst direction and overlapping at least the control line and a secondlight-shield formed along a second direction, crossing the firstlight-shield and overlapping at least the signal line; a liquid crystallayer between the first substrate and the second substrate; and a spacerwhich maintains a gap between the first substrate and the secondsubstrate, wherein the spacer overlaps a crossing region where the firstlight-shield and the second light-shield cross each other and includesan exposed region outside the light-shielding layer, the control line,and the signal line, and the exposed region overlaps the color filter ina planar view.
 2. The liquid crystal display of claim 1, wherein a widthof the spacer along the first direction is greater than that of thesecond light-shield along the first direction, and a width of the spaceralong the second direction is greater than that of the firstlight-shield along the second direction.
 3. The liquid crystal displayof claim 1, wherein the spacer is overlaid on a center of the crossingregion.
 4. The liquid crystal display of claim 1, wherein the exposedregion is defined by an edge of the spacer and the first and secondlight-shields.
 5. The liquid crystal display of claim 1, wherein thespacer includes a first overlapping region overlapping the first pixelelectrode, and the first overlapping region includes the exposed region.6. The liquid crystal display of claim 5, wherein the first substratefurther comprises a second pixel electrode adjacent to the first pixelelectrode along the first direction with the second light-shieldtherebetween in the planar view, the spacer includes a secondoverlapping region overlapping the second pixel electrode, and an areaof the first overlapping region is the same as that of the secondoverlapping region.
 7. The liquid crystal display of claim 5, whereinthe first substrate further comprises a second pixel electrode adjacentto the first pixel electrode along the first direction with the secondlight-shield therebetween in the planar view, the spacer includes asecond overlapping region overlapping the second pixel electrode, and anarea of the first overlapping region is greater than that of the secondoverlapping region.
 8. The liquid crystal display of claim 5, whereinthe first pixel electrode comprises a reflecting electrode and atransparent protecting electrode stacked on the reflecting electrode,and the protecting electrode covers an upper surface and a side surfaceof the reflecting electrode.
 9. The liquid crystal display of claim 8,wherein an area of a region where the spacer and the reflectingelectrode overlap each other is less than that of a region where thespacer and the protecting electrode overlap each other, and is greaterthan that of the exposed region.
 10. The liquid crystal display of claim8, wherein at least a part of the spacer is formed on the protectingelectrode.
 11. The liquid crystal display of claim 1, wherein the firstsubstrate comprises a plurality of pixel electrodes, the secondsubstrate comprises a common electrode opposing the plurality of pixelelectrodes, and the spacer is formed on the common electrode andprojects from the second substrate to the first substrate.
 12. Theliquid crystal display of claim 1, wherein a width of the firstlight-shield along the second direction is constant between a positionclose to the crossing region and a position separated from the crossingregion.
 13. The liquid crystal display of claim 1, wherein the exposedregion comprises a first exposed region and a second exposed region, andthe second exposed region opposes the first exposed region through thefirst or second light-shield.
 14. The liquid crystal display of claim13, wherein the exposed region further comprises a third exposed region,the second exposed region opposes the first exposed region through thesecond light-shield, and the third exposed region opposes the firstexposed region through the first light-shield.
 15. The liquid crystaldisplay of claim 14, wherein the exposed region further comprises afourth exposed region, and the fourth exposed region opposes the secondexposed region through the first light-shield and opposes the thirdexposed region through the second light-shield.